Ok but is there room for the idea that your intuitions are incorrect? Plenty of things in the world are counter-intuitive. ‘docker-compose up -d’ works the same whether it’s one container or fifty.
Computer resources are measured in bits and clock cycles, not the number of containers and volumes. It’s entirely possible (even likely) that an all-in-one container will be more resource-heavy than the same services split across multiple containers. Logging from an all-in-one will be a jumbled mess, troubleshooting issues or making changes will be annoying, it’s worse in every way except the length of output from ‘docker ps’
but there is a reason i just explained it to you